In a typical vehicular environment, an internal combustion engine will be resiliently mounted on the frame of the vehicle and the exhaust system for the engine will include a rigid exhaust pipe extending from the exhaust manifold of the engine to a muffler with the hot exhaust gases then being discharged from the muffler through a tail pipe.
Such a system poses significant problems in the provision of a reliable, simple and inexpensive support for the muffler.
Because of the resilient engine mount, the engine will vibrate in many planes during operation, even when the vehicle is not moving. Such vibrations will be imparted to the muffler through the rigid exhaust pipe causing the muffler to similarly vibrate. Movement of the vehicle, particularly over rough terrain, will cause further shock and vibration of the muffler. The muffler support must, of course, have sufficient strength to support the weight of the muffler and prevent vibration and shock from causing failure of the exhaust pipe or muffler.
The heat of the hot exhaust gases also presents a problem in that such heat will cause the exhaust pipe and muffler to expand and shift relative to the engine. The muffler support must also allow for relief of these stresses.
The hot exhaust gases further present a problem in that the muffler becomes quite hot during operation and such heat will be transmitted by conduction to the muffler support. As a consequence, the muffler support must be able to withstand high temperatures without failure. This problem is increased in instances wherein the design of the vehicle makes it necessary to locate the muffler in a crowded space with a minimal amount of cooling air flow past the muffler.
Corrosion from road contaminates and oxidation are further problems to be considered in providing a suitable muffler support which will not fail prematurely.
Attempts have been made to mount the muffler rigidly to the engine so that there is no relative movement of the engine and muffler due to shock and vibration. In general, such attempts have not been satisfactory as the rigid mounts are subject to breaking and they restrain the muffler in such manner that substantial stresses are imposed on the muffler because of thermal expansion thereof.
Flexible rubber belting straps members have also been used to suspend the mufflers. Such rubber belting straps do aid in protecting the muffler against shock, vibration and thermal expansion, but they are adversely affected by high temperatures and have a relatively short life before failure.
In summary, there is a need for a simple, inexpensive and reliable muffler mount which will bear the weight of the muffler, which will withstand shock, vibration and thermal expansion forces, which is heat resistant, and which is resistant to corrosion and oxidation.